Jez Spinks

The next-generation Astra hatchback expected to spearhead Holden’s future assault on the vital small-car class will be smaller, lighter, feature turbocharged three-cylinder engines, and introduce a faster VXR - this time in five-door form.

The new Astra due out late 2015 in Europe – and depicted in our artist's illustration above – will sit on a modified version of the current model’s ‘Delta II’ platform, before the generation after that switches to General Motors’ new modular architecture being introduced from 2018.

General Motors’ European arm, Opel, says it is targeting significant weight savings of up to 150kg for the Astra despite carrying over the underpinnings.

“We are targeting 150kg for weight reduction [for the new Astra OPC],” says Wilfried Diehl, Opel’s performance variance manager. “It is not easy, of course. You have so many airbags now and cars are getting bigger all the time.”

A bit less sheetmetal will help, though. Diehl, who chiefly operates on the OPC side of the business, revealed the fifth iteration of the Astra since its debut in 1991 will buck the trend for new cars being bigger than the models they replace.

“The car will be a little bit smaller than the current Astra,” he said. “You see it with the VW Golf [one of the most compact small cars]… The current Astra is much longer than the Golf and it makes no sense to have these big cars in this segment. If you look at the first [Opel] Kadet, how small it is … now you have a limousine.

“Now we have to go back to a smaller cars with very good packaging inside so that you have the same space inside [as before], the [same] luggage capacity, with the smaller overall size outside. This is the strategy we follow: to reduce weight, to improve fuel efficiency and CO2.

Opel is planning to keep the new Astra to five-door hatch and four-door sedan body styles only – including the Sports Tourer wagon. The three-door Astra GTC, which in current form is one of a handful of Opels being imported to Australia from 2015, looks set to be dropped, leaving the Corsa and Adam as the three-door small car options for buyers.

The 2015 Opel Astra will feature a range of turbocharged engines, with the smallest a 1.0-litre three-cylinder available in two different forms at least. The Adam city car was first to get the new units that form part of 17 new engines being introduced by 2018.

There are 66kW and 85kW versions, both sharing maximum torque of 166Nm that’s produced handily between 1800 and 4700rpm. Also part of the plan are 1.2-, 1.4- and 1.6-litre turbo four-cylinders.

The 1.0-litre is currently available only with a manual gearbox but an automatic is on its way.

Opel has ruled out dual-clutch transmissions, at least for now, mainly because the company doesn't see enough benefits in return for the investment.

Holden is also importing the current Astra VXR hot-hatch in 2015, though its lifespan will end just two years later as its replacement steps in.

Diehl said the VXR would be a five-door hatch this time, while Opel was considering whether to go with an updated version of the current car’s 206kW 2.0-litre turbo four-cylinder or downsize to a 1.6-litre turbo.

Either way, the new Astra VXR will gain some extra power and combine that with the hatch’s reduced weight to be quicker than the current model that sprints to 100km/h in about 6.0 seconds.

CarAdvice spies caught a peek at the Astra’s interior makeover earlier this year.

Images confirmed the Astra will adopt a similar two-tier dash design to the new Corsa being launched imminently in Europe.

The upper tier features the MyLink touchscreen with entertainment and navigation controls; the lower tier presents the controls for the climate system.

The 2015 Astra will also follow the Corsa with a notable lift in the quality of its cabin materials.

Holden is expected to bring at least one version of the new Corsa that launches imminently in Europe - either in high-spec regular form or hot-hatch VXR guise, with the Barina continuing as its price leader in the price sensitive city car segment.

The company could opt for a similar strategy in the small car class by offering versions of the next-generation Cruze as cheaper alternatives to the Astra.